Regeneration method of sepiolite-based nano flower-shaped cobalt page silicate catalyst

Abstract

The invention discloses a regeneration method of a sepiolite-based nano flower-shaped cobalt page silicate catalyst, and relates to the technical field of catalysts. The method comprises the steps of S1 to S3; according to the catalyst regeneration treatment method, the steps of re-calcination, acid leaching and the like are added on the basis of an original catalyst preparation method, reagents used for regeneration treatment only relate to inorganic acid such as ammonium fluoride, concentrated nitric acid and concentrated hydrochloric acid, a precipitator is urea or other substitutes such as hydrazine hydrate, raw materials are easy to obtain, the method is simple, and the deactivated catalyst is easy to regenerate on a large scale; after cyclic regeneration, when the sepiolite-based nano flower-like phyllosilicate catalyst is applied to hydrogen production by glycerol steam reforming, under proper conditions, the raw material conversion rate in a single reaction period can be greater than or equal to 70%, the hydrogen yield is greater than or equal to 50%, and the service life is greater than or equal to 500 hours; the main hydrogen production performance index and inactivation trend of reforming hydrogen production of the catalyst are highly consistent with those of a fresh catalyst, and the large-scale regeneration treatment requirement of the reforming hydrogen production catalyst is met.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and particularly to a regeneration method for a sepiolite-based nanoflower-shaped cobalt phyllosilicate catalyst. Background Art

[0002] To broaden the technical path blueprint for achieving the "dual carbon" goal and promote the development of clean energy and renewable hydrogen energy, biomass and its derivatives are regarded as a carbon-negative resource and a dark horse among many renewable hydrogen sources. In addition, bioglycerol, as a by-product of biodiesel production by the transesterification method, has characteristics such as high moisture content, high salt content, and low grade. Facing the already saturated glycerol commercial market, bioglycerol urgently needs effective carbon-neutral conversion and utilization pathways. Catalytic steam reforming for hydrogen production is an effective technical path, which can convert glycerol into H2 and CO2 under relatively mild thermodynamic conditions to obtain renewable blue hydrogen.

[0003] Catalytic steam reforming is a structure-sensitive thermochemical reaction, and the core of the reaction is always an efficient and stable catalyst. Considering economy, transition metals (Ni, Co, and Cu) are selected as active metals instead of noble metals. In addition, when the transition metal (Ni, Co, and Cu) sites are in the zero-valent state, the selective bond-breaking ability for the C-C and C-H bonds of glycerol is close to that of noble metal-based catalysts. However, the catalyst mainly deactivates rapidly in the short term due to carbon deposition and metal sintering, which has always been a key scientific problem in the steam reforming process for hydrogen production; Amorphous sepiolite, as a phyllosilicate catalyst carrier and silicon source, is derived from the alkali activation treatment of sepiolite ore. Substantially, it is a low-crystallinity aluminosilicate microparticle, as detailed in Chinese Patent Application No. 202311351405.5. During the hydrothermal precipitation preparation process, the amorphous sepiolite is treated with the alkaline radicals (NH 4+ / HCO 3- / OH -)Erosion occurs, releasing silicate ions in a homogeneous and slow-release manner, which coordinate with active metals to form phyllosilicates. Through Ostwald ripening, they grow and crystallize without orientation, forming flower-like phyllosilicate nanosheets. The sepiolite-based flower-like phyllosilicates are calcined to remove crystal water and residual alkaline root ions, becoming an ordered crystal oxide catalyst with a high specific surface area, strong metal-support interaction, balanced acid-base sites, and high metal dispersion. However, this catalyst still faces inherent deactivation problems in the industrial application of steam reforming, such as carbon deposition and metal sintering. That is, when the reaction temperature is higher than its Talbot temperature, the nano metal particles supported on the catalyst spontaneously and irreversibly undergo Ostwald ripening and particle migration and coalescence on the catalyst surface under high temperature, high water vapor partial pressure, and complex redox atmosphere, forming new large-size nano metal particles. At the same time, due to the size effect, large-size nano metal particles have a higher proportion of step / platform sites, resulting in a decrease in the C-C bond breaking efficiency, making surface-bulk carburization prone to occur, accelerating the carbon deposition rate, and gradually evolving into the deposition of nanotubes / graphite carbon layers, which encapsulate the nano metal particles and cover the active metal sites, leading to rapid deactivation of the catalyst. To address the above problems, the inventor proposes a regeneration method for a sepiolite-based nano-flower-like cobalt phyllosilicate catalyst to solve the above problems. Summary of the Invention

[0004] To solve the problems of rapid catalyst deactivation and low catalyst regeneration performance and cyclic service life; the purpose of the present invention is to provide a regeneration method for a sepiolite-based nano-flower-like cobalt phyllosilicate catalyst.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions: A regeneration method for a sepiolite-based nano-flower-like cobalt phyllosilicate catalyst, comprising the following steps: S1. Place the deactivated catalyst in a tubular furnace and re-calcine it in an air atmosphere to remove carbon deposition; S2. Add the re-calcined catalyst to ammonium fluoride, supplemented with an inorganic strong acid deionized aqueous solution, heat and stir evenly. After the supported metal is leached, add the precipitant urea and then transfer it into a high-pressure reaction kettle; S3. After the hydrothermal reaction of the re-calcined catalyst, after cooling, standing, and aging, carry out suction filtration, washing, drying, and grinding and screening treatments, and then successively calcine it in an air atmosphere and a reducing atmosphere in a tubular furnace to obtain a regenerated nano-flower-like cobalt phyllosilicate catalyst.

[0006] Preferably, in S2, the inorganic strong acid deionized aqueous solution is any one of concentrated nitric acid, concentrated hydrochloric acid, or a mixture of concentrated nitric acid and concentrated hydrochloric acid. During the catalyst regeneration process in S2, the molar ratio of urea to metal ions is 50-80.

[0007] By adopting the above technical solution and this ratio, it can effectively ensure the loading of active metals (Ni, Co, and Cu) in the form of phyllosilicate. Too low or too high precipitant concentration will affect the restoration of the crystal phase and morphology of the regenerated catalyst.

[0008] Preferably, in S2, the specific process of the hydrothermal reaction is as follows: adjust the temperature of the polytetrafluoroethylene liner of the autoclave to 200 - 250 °C, the rotation speed to 100 - 200 r / min, and the time to 12 - 24 h.

[0009] Preferably, in S3, the specific process of the standing and aging treatment is as follows: stop stirring the autoclave and naturally cool it to room temperature, and then stand for 12 - 24 h.

[0010] Preferably, in S3, the temperature conditions for calcination and recalcination in air atmosphere are 500 - 700 °C, and the time is 2 - 4 h. The temperature conditions for calcination in reducing atmosphere are 600 - 800 °C, and the time is 2 - 4 h.

[0011] By adopting the above technical solution and the above regeneration conditions, it is beneficial for the stable occurrence of active metals in the form of nanoflower - shaped phyllosilicate, making the performance indicators of the regenerated catalyst fully restored.

[0012] Preferably, the reducing atmosphere is a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%.

[0013] By adopting the above technical solution and the above conditions, it is beneficial for the reduction of active metals and improves the service life of the obtained regenerated catalyst.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the catalyst regeneration treatment method of the present invention, only steps such as recalcination and acid leaching are added on the basis of the original catalyst preparation method. The reagents used in the regeneration treatment only involve inorganic acids such as ammonium fluoride, concentrated nitric acid, and concentrated hydrochloric acid, and the precipitant is urea or other substitutes such as hydrazine hydrate. The raw materials are easily available, the method is simple, and it is easy to scale - up the regeneration of deactivated catalysts; 2. After the sepiolite - based nanoflower - shaped phyllosilicate catalyst of the present invention is recycled and regenerated, when applied to glycerol steam reforming for hydrogen production, under suitable conditions, it can achieve a raw material conversion rate ≥70%, a hydrogen yield ≥50% within a single reaction cycle, and a service life ≥500 h. The main hydrogen production performance indicators and deactivation trend of the catalyst for reforming to produce hydrogen are highly consistent with those of the fresh catalyst, meeting the requirements for the scale - up regeneration treatment of reforming to produce hydrogen catalysts; 3. The regeneration method of the sepiolite-based nano-flower-like phyllosilicate catalyst of the present invention can achieve the redispersion and size recovery of sintered nano-metal particles compared with the thermal calcination regeneration method. The process is controllable, practical and economical, avoiding the continuous increase in the size of nano-metal particles and the carbon deposition rate caused by the irreversibility of metal sintering, and enhancing the catalyst regeneration performance and cyclic service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0016] Figure 1 X-ray diffraction patterns of fresh and regenerated catalysts in Examples 1 to 5 of the present invention.

[0017] Figure 2 Scanning electron microscope images of fresh and regenerated catalysts in Examples 1 to 5 of the present invention.

[0018] Table 1 Performance index table of glycerol steam reforming for hydrogen production of fresh and regenerated catalysts in Examples 1 to 5 of the present invention.

[0019] Table 2 Key physical and chemical parameter table of fresh and regenerated catalysts in Examples 1 to 5 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0021] Example 1: As Figure 1-2 shown, the present invention provides a regeneration method for a sepiolite-based nano-flower-like cobalt phyllosilicate catalyst. The nickel content of the active component before the inactivation of the sepiolite-based nano-flower-like nickel phyllosilicate catalyst is 5.05 wt.%, and 99.4% of the total nickel load exists in the form of phyllosilicate. The remaining components of the catalyst are amorphous sepiolite. The regeneration method is as follows: S1. Take 0.2 g of the inactivated catalyst and place it in a tubular furnace. Under an air atmosphere, heat it from room temperature to 500 °C at a heating rate of 2 °C / min, keep it calcined at a constant temperature for 2 h, and then cool it to room temperature to obtain solid powder I; S2. Place solid powder I in a 100 mL round-bottomed beaker, add 10 mL of deionized water, and stir evenly to form suspension I; Weigh 0.02 g of ammonium fluoride, 0.02 g of concentrated nitric acid, and 0.004 g of concentrated hydrochloric acid, add them to suspension I and dissolve completely, and place them in a water bath at 80 °C with constant stirring for 4 h to form suspension II; Weigh 0.83 g of urea (the molar ratio of urea to metal ions is 80), add it to suspension II and dissolve completely, and stir well to form suspension III; Add suspension III into an autoclave, adjust the temperature of the autoclave to 200 °C, the rotation speed to 100 r / min, and the time to 24 h; S3. After the hydrothermal precipitation is completed, the autoclave is naturally cooled to room temperature and aged and left standing for 12 h to form solid-liquid mixture I; Solid-liquid mixture I is filtered, washed, dried, and sieved to obtain solid powder II; Place solid powder II in a tube furnace, heat it from room temperature to 500 °C at a heating rate of 2 °C / min under an air atmosphere, keep it at a constant temperature for 2 h, and then cool it to room temperature; Then introduce a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%, heat it from room temperature to 600 °C at a heating rate of 2 °C / min, keep it at a constant temperature for 2 h, and then cool it to room temperature to obtain the sepiolite-based nano-flower-like nickel phyllosilicate regenerated catalyst, marked as 5Ni / SEP-1, where SEP is the English abbreviation of sepiolite (Sepiolite), and 1 is the catalyst regeneration times.

[0022] Through characterization and detection calculations, the nickel content of the regenerated catalyst 5Ni / SEP-1 is 5.03 wt.%, which is 99.2% of the total nickel load in the form of phyllosilicate. Compared with the fresh catalyst, the difference value is within the characterization and detection error range (±0.5%).

[0023] Example 2: As Figure 1-2 shown, the present invention provides a regeneration method for a sepiolite-based nano-flower-like cobalt phyllosilicate catalyst. Before deactivation, the active ingredient cobalt content of the sepiolite-based nano-flower-like cobalt phyllosilicate catalyst is 10.09 wt.%, of which 99.2% is the total nickel load in the form of phyllosilicate, and the rest of the catalyst components are amorphous sepiolite. The regeneration method is as follows: S1. Take 0.4 g of the deactivated catalyst and place it in a tube furnace. Heat it from room temperature to 600 °C at a heating rate of 3 °C / min under an air atmosphere, keep it at a constant temperature for 1.5 h, and then cool it to room temperature to obtain solid powder I; S2. Place solid powder I in a 100 mL round-bottomed beaker, add 20 mL of deionized water, and stir evenly to form suspension I; Weigh 0.12 g of ammonium fluoride and 0.12 g of concentrated nitric acid, add them to suspension I and dissolve completely, then place them in a water bath at 85 °C and stir constantly for 3 h to form suspension II; Weigh 2.04 g of urea (the molar ratio of urea to metal ions is 50), add it to suspension II and dissolve completely, and form suspension III after sufficient stirring; Add suspension III into the autoclave, adjust the temperature of the autoclave to 210 °C, the rotation speed to 120 r / min, and the time to 22 h; S3. After the hydrothermal precipitation ends, the autoclave is naturally cooled to room temperature and aged and left standing for 14 h to form solid-liquid mixture I; Solid-liquid mixture I is filtered, washed, dried, and sieved to obtain solid powder II; Put solid powder II in a tube furnace, heat it from room temperature to 600 °C at a heating rate of 3 °C / min under an air atmosphere, keep it at a constant temperature for calcination for 1.5 h, and then cool it to room temperature; Then introduce a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%, heat it from room temperature to 700 °C at a heating rate of 3 °C / min, keep it at a constant temperature for calcination for 1.5 h, and then cool it to room temperature to obtain the sepiolite-based nanoscale flower-like cobalt phyllosilicate regenerated catalyst, marked as 10Ni / SEP-1. Put the above regenerated catalyst back into the reactor and use it for 500 h until it is deactivated significantly, then take it out again for regeneration treatment. In this way, the reaction-regeneration cycle is carried out three times in total, and finally the sepiolite-based nanoscale flower-like cobalt phyllosilicate regenerated catalyst, marked as 10Ni / SEP-3, is obtained.

[0024] Through characterization and detection and calculation, the cobalt content of the regenerated catalyst 10Co / SEP-3 is 10.06 wt.%, and 99.0% of the total nickel load exists in the form of phyllosilicate. Compared with the fresh catalyst, the difference value is within the characterization and detection error range (±0.5%).

[0025] Example 3: As Figure 1-2 shown, the present invention provides a regeneration method for a sepiolite-based nanoscale flower-like cobalt phyllosilicate catalyst. The active ingredient copper content of the sepiolite-based nanoscale flower-like copper phyllosilicate catalyst before deactivation is 15.10 wt.%, and 98.9% of the total nickel load exists in the form of phyllosilicate. The remaining components of the catalyst are amorphous sepiolite. The regeneration method is as follows: S1. Take 0.6 g of the deactivated catalyst and place it in a tube furnace. Heat it from room temperature to 700 °C at a heating rate of 4 °C / min under an air atmosphere, keep it at a constant temperature for calcination for 1 h, and then cool it to room temperature to obtain solid powder I; S2. Place solid powder I in a 100 mL round-bottomed flask, add 30 mL of deionized water, and stir evenly to form suspension I; Weigh 0.09 g of ammonium fluoride, 0.09 g of concentrated nitric acid, and 0.048 g of concentrated hydrochloric acid, add them to suspension I and dissolve completely, and place them in a water bath at 90 °C for constant-temperature stirring for 2.5 h to form suspension II; Weigh 5.13 g of urea (the molar ratio of urea to metal ions is 60), add it to suspension II and dissolve completely, and form suspension III after sufficient stirring; Add suspension III to the autoclave, adjust the temperature of the autoclave to 220 °C, the rotation speed to 140 r / min, and the time to 20 h; S3. After the hydrothermal precipitation is completed, the autoclave is naturally cooled to room temperature and aged and left standing for 16 h to form solid-liquid mixture I; Solid-liquid mixture I is filtered, washed, dried, and sieved to obtain solid powder II. The solid powder; Put solid powder II in a tubular furnace, and raise the temperature from room temperature to 700 °C at a heating rate of 4 °C / min under an air atmosphere, keep it at a constant temperature for 1 h, and then cool it to room temperature; Then introduce a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%, raise the temperature from room temperature to 800 °C at a heating rate of 4 °C / min, keep it at a constant temperature for 1 h, and then cool it to room temperature to obtain the sepiolite-based nanoscale flower-like cobalt phyllosilicate regenerated catalyst, labeled 15Cu / SEP-1. Put the above regenerated catalyst back into the reactor and use it for 500 h until it is significantly deactivated, and then take it out for regeneration treatment again. Such reaction-regeneration cycles are carried out a total of five times, and finally a sepiolite-based nanoscale flower-like copper phyllosilicate regenerated catalyst, labeled 15Cu / SEP-5, is obtained.

[0026] Through characterization and detection calculations, the copper content of the regenerated catalyst 15Cu / SEP-5 is 15.04 wt.%, which is 98.4% of the total copper load in the form of phyllosilicate. Compared with the fresh catalyst, the difference value is within the characterization and detection error range (±0.5%).

[0027] Example 4: As Figure 1-2 shown, the present invention provides a regeneration method for a sepiolite-based nanoscale flower-like cobalt phyllosilicate catalyst. Before deactivation, the active component nickel content of the sepiolite-based nanoscale flower-like nickel cobalt phyllosilicate catalyst is 9.90 wt.%, and the cobalt content is 10.07 wt.%, among which 98.7% of the total nickel cobalt load exists in the form of phyllosilicate. The rest of the catalyst components are amorphous sepiolite. The regeneration method is as follows: S1. Take 0.8 g of the deactivated catalyst and place it in a tubular furnace. Raise the temperature from room temperature to 600 °C at a heating rate of 4 °C / min under an air atmosphere, keep it at a constant temperature for 1.5 h, and then cool it to room temperature to obtain solid powder I; S2. Place solid powder I in a 100 mL round-bottomed flask, add 40 mL of deionized water, and stir evenly to form suspension I; Weigh 0.16 g of ammonium fluoride and 0.064 g of concentrated hydrochloric acid, add them to suspension I and dissolve completely, and place them in a water bath at 95 °C with constant stirring for 2 h to form suspension II; Weigh 10.20 g of urea (the molar ratio of urea to metal ions is 65), add it to suspension II and dissolve completely, and stir well to form suspension III; Add suspension III into the autoclave, adjust the temperature of the autoclave to 230 °C, the rotation speed to 160 r / min, and the time to 18 h; S3. After the hydrothermal precipitation, the autoclave is naturally cooled to room temperature and aged and left standing for 14 h to form solid-liquid mixture I; Solid-liquid mixture I is filtered, washed, dried, and sieved to obtain solid powder II. Put solid powder II in a tube furnace, heat it from room temperature to 600 °C at a heating rate of 4 °C / min under an air atmosphere, keep it at a constant temperature for 1.5 h, and then cool it to room temperature; Then introduce a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%, heat it from room temperature to 700 °C at a heating rate of 4 °C / min, keep it at a constant temperature for 1 h, and then cool it to room temperature to obtain the sepiolite-based nanoscale flower-like cobalt phyllosilicate regenerated catalyst, marked as 10Ni10Co / SEP-1. Put the above regenerated catalyst back into the reactor and use it for 500 h until it is significantly deactivated, then take it out again for regeneration treatment. Such reaction-regeneration cycles are carried out a total of 7 times, and finally, the sepiolite-based nanoscale flower-like copper phyllosilicate regenerated catalyst, marked as 10Ni10Co / SEP-7, is obtained.

[0028] Through characterization and detection calculations, the nickel content of the regenerated catalyst 10Ni10Co / SEP-7 is 9.86 wt.%, the cobalt content is 10.01 wt.%, and 98.2% of the total nickel-cobalt load exists in the form of phyllosilicate. Compared with the fresh catalyst, the difference value is within the characterization and detection error range (±0.5%).

[0029] Example 5: As Figure 1-2 shown, a regeneration method for a sepiolite-based nanoscale flower-like cobalt phyllosilicate catalyst. Before deactivation, the active component nickel content of the sepiolite-based nanoscale flower-like nickel-cobalt-copper phyllosilicate catalyst is 10.04 wt.%, the cobalt content is 9.95 wt.%, and the copper content is 5.02 wt.%. 98.0% of the total nickel-cobalt-copper load exists in the form of phyllosilicate, and the rest of the catalyst components are amorphous sepiolite. The regeneration method is as follows: S1. Take 1.0 g of the deactivated catalyst and place it in a tubular furnace. Under an air atmosphere, heat it from room temperature to 550 °C at a heating rate of 3 °C / min, keep it at a constant temperature for calcination for 2 h, and then cool it to room temperature to obtain solid powder I. S2. Place solid powder I in a 100 mL round-bottomed flask, add 50 mL of deionized water, and stir evenly to form suspension I. Weigh 0.20 g of ammonium fluoride, 0.20 g of concentrated nitric acid, and 0.06 g of concentrated hydrochloric acid, add them to suspension I and dissolve completely, and place it in a water bath at 90 °C and stir constantly for 2 h to form suspension II. Weigh 17.50 g of urea (the molar ratio of urea to metal ions is 70), add it to suspension II and dissolve completely, and stir well to form suspension III. Add suspension III into a high-pressure reactor, adjust the temperature of the high-pressure reactor to 250 °C, the rotation speed to 200 r / min, and the time to 12 h. S3. After the hydrothermal precipitation is completed, the high-pressure reactor is naturally cooled to room temperature and aged and left standing for 12 h to form solid-liquid mixture I. Solid-liquid mixture I is filtered, washed, dried, and sieved to obtain solid powder II. Place solid powder II in a tubular furnace. Under an air atmosphere, heat it from room temperature to 550 °C at a heating rate of 4 °C / min, keep it at a constant temperature for calcination for 2 h, and then cool it to room temperature. Then introduce a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%, heat it from room temperature to 650 °C at a heating rate of 4 °C / min, keep it at a constant temperature for calcination for 1 h, and then cool it to room temperature to obtain the sepiolite-based nanoscale flower-like cobalt phyllosilicate regenerated catalyst, labeled 10Ni10Co5Cu / SEP-1. Put the above regenerated catalyst back into the reactor and use it for 500 h until it is significantly deactivated, then take it out again for regeneration treatment. Such reaction-regeneration cycles are carried out a total of 10 times, and finally obtain the sepiolite-based nanoscale flower-like copper phyllosilicate regenerated catalyst, labeled 10Ni10Co5Cu / SEP-10.

[0030] Through characterization and detection calculations, the nickel content of the regenerated catalyst 10Ni10Co5Cu / SEP-10 is 9.81 wt.%, the cobalt content is 9.89 wt.%, and the copper content is 4.95 wt.%. Among them, 97.5% of the total nickel and cobalt load exists in the form of phyllosilicate. Compared with the fresh catalyst, the difference value is within the characterization and detection error range (±0.5%).

[0031] Example VI: As Figure 1-2 shown, refer to Figure 1, determination of the crystal phase of the sepiolite-based nano-flower-like phyllosilicate catalyst before and after regeneration. According to the JCPDF card, obvious diffraction peaks of the phyllosilicate phase appear at 2θ = 20.0°, 28.3°, 34.9° and 61.9°. At the same time, the consistent diffraction peak intensities indicate that the crystallinity of the phyllosilicate phase remains unchanged before and after the catalyst regeneration, and no other occurrence forms and crystal phase compositions of the active metals (Ni, Co and Cu) are found due to the regeneration of the catalyst; Reference Figure 2 , a nano-flower-like morphology formed by the stacking of a large number of nanosheets can be observed, and its morphology does not change with the catalyst regeneration cycle.

[0032] Example 7. Referring to Table 1, comparison of the key physical and chemical properties of the sepiolite-based phyllosilicate catalyst after regeneration and the fresh catalyst;

[0033] From the above results, it can be concluded that the key physical and chemical properties of the catalyst in the embodiments of the present invention do not change significantly with the cyclic regeneration treatment, ensuring the activity recovery of the structure-sensitive glycerol steam reforming for hydrogen production reaction.

[0034] Example 8. Referring to Table 2, the sepiolite-based nano-flower-like phyllosilicate catalyst after regeneration is put into the glycerol steam reforming for hydrogen production test. 0.2 g - 1.0 g of the regenerated catalyst in the above Examples 1 - 5 is placed in a fixed-bed reactor, the feed rate of the reactant raw material is 10 g / h - 25 g / h, the molar ratio of water to carbon in the raw material (S / C) is 1.5 - 3, the reaction temperature is 500 °C - 700 °C, and any reaction cycle in the reaction-regeneration cycle is 500 h.

[0035]

[0036] From the above results, it can be concluded that the regeneration method in the embodiments of the present invention can achieve a glycerol conversion rate ≥ 70%, a hydrogen production rate ≥ 50%, a service life of a single reaction cycle ≥ 500 h, and a cumulative service life of cycling ≥ 5500 h for the sepiolite phyllosilicate catalyst.

[0037] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A regeneration method for a sepiolite-based nanoflower cobalt phyllosilicate catalyst, characterized in that, It includes the following steps: S1. Place the deactivated catalyst in a tube furnace and calcine it again in an air atmosphere to remove carbon deposits; S2. Add the recalcined catalyst to ammonium fluoride, supplemented with an inorganic strong acid deionized aqueous solution, heat and stir evenly. After the supported metal is leached, add the precipitant urea and then transfer it into a high-pressure reactor; S3. After the hydrothermal reaction of the recalcined catalyst is completed, after cooling, standing, and aging, carry out suction filtration, washing, drying, and grinding and screening treatments, and then calcine it successively in an air atmosphere and a reducing atmosphere in a tube furnace to obtain a regenerated nano-flower-shaped cobalt phyllosilicate catalyst.

2. The regeneration method of a sepiolite-based nanoflower cobalt phyllosilicate catalyst as claimed in claim 1, wherein, In S2, the inorganic strong acid deionized aqueous solution is any one of concentrated nitric acid, concentrated hydrochloric acid, or a mixture of concentrated nitric acid and concentrated hydrochloric acid. During the catalyst regeneration process in S2, the molar ratio of urea to metal ions is 50-80.

3. The regeneration method of a sepiolite-based nanoflower cobalt phyllosilicate catalyst according to claim 1, characterized in that, In S2, the specific process of the hydrothermal reaction is as follows: Adjust the temperature of the polytetrafluoroethylene liner of the high-pressure reactor to 200-250 °C, the rotation speed to 100-200 r / min, and the time to 12-24 h.

4. The regeneration method of a sepiolite-based nanoflower-shaped cobalt phyllosilicate catalyst as described in claim 1, characterized in that, In S3, the specific process of the standing and aging treatments is as follows: Stop stirring the high-pressure reactor and naturally cool it to room temperature, and then stand for 12-24 h.

5. The regeneration method of a sepiolite-based nanoflower-shaped cobalt phyllosilicate catalyst as described in claim 1, characterized in that, In S3, the temperature conditions for calcination in the air atmosphere and recalcination are 500-700 °C, and the time is 2-4 h. The temperature conditions for calcination in the reducing atmosphere are 600-800 °C, and the time is 2-4 h.

6. The regeneration method of a sepiolite-based nanoflower cobalt phyllosilicate catalyst according to claim 1, characterized in that, The reducing atmosphere is a mixed gas of hydrogen and nitrogen with a hydrogen volume fraction of 10%.

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